Pyrethrin synergist



Patented Dec. 2, 1947 UNITED STATES PATENT OFFICE PYRETHRIN SYNERGISTMartin E. Synerholm, Hastings on Hudson, N. Y., assignor to BoyceThompson Institute for Plant Research, Inc., a corporation of New YorkNo Drawing. Application August a, 1944, Serial No. 547.982

3 Claims. (Cl. 167-24) those comprising pyrethrin, or the like, are veryefiicient in combating insect pests, such as flies, moths, ormosquitoes.

I have discovered a class of esters of piperic acid, prepared by knownmethods of esterification, and having the formulae where R isrepresented by a radical of the group consisting of ethyl, n-propyl,isopropyl, n-butyl, allyl, benzyl, cinnamyl, and tetrahydrofuriuryl,which'are suitable for insecticidal purposes. The com unds areexceptional synergistic agents in compositions comprising pyrethrin in aspray medium, advantageously in a mutual solvent. Spray compositionscomprising one or more of the compounds and pyrethrin in a hydrocarbonor mineral oil, such as odorless kerosene or naphtha are especiallyeffective insecticides.

The aforementioned compounds increase the toxic effect of pyrethrin to avery marked extent and when they are incorporated in a suitable sprayingmedium with pyrethrin or like extracts the resulting composition hasmore killing effect against such insects as the ordinary housefly thanthe combined eifects of the pyrethrin and the compound when used alone.The invention provides an improved insecticidal composition comprisingone or more piperic acid esters of the group consisting of where R. is aradical of the group consisting of ethyl, n-propyl, iso-propyl, n-butyl,allyl, benzyl, cinnamyl. and tetrahydrofurfuryl, and pyrethrin in aliquid spray medium, for example, of hydrocarbon character. such asodorless kerosene or naphtha.

The synergistic effect of the compounds is shown in the following tablein which the results were obtained by the Standard Feet-Grady metha 2 adwith five-day old flies as described on pages 92 to 98 of PyrethrumFlowers by C. B. Gnadinger, 1936 edition, with compositions comprisingcompounds represented by the formulae in which the various compounds areidentified by the radical R, and 0.025 gm. pyrethrins per 100 ml. ofodorless kerosene:

O'II Ad] 1? Grams per Per Cent at R 100 ml. Kill g? Ethyl 0.5 91 50 0.2568 46 B-Bromoethyl 0.5 87 5c 82 n-Propyl 0. 5 98 76 0.25 91 58 86 0.12577 56 72 Iso-propyl 0. 5 100 58 98 0. 125 65 51 65 .B 1 2'3 8% i8romoiso to y p p 0.5 92 47 93 0. 25 84 46 85 0. 05 38 46 43o-Chlorophenyl I 0. l 63 46 65 0.05 62 41 47 n-Butyl 0. 5 98 68 94 0.2594 68 '85 0.125 90 68 79 2-nitroisobutyl 0.5 60 36 73 0. 25 71 47 73n-Amyl 0.5 95 72 0.25 81* 53 Ally] 1.0 93 5 it 2% 0.25 35 0.1 44 50 0.0532 46 Cinnamyl 1.0 65 47 0.25 66 56 Benzyl 0.5 95 58 0.25 82 56Tetrahydroiuriuryl. 0. 25 94 58 0. 06 66 5s Bornyl 1.0 97 49 0.5 79 47Compounds used without pyrethrins Grams Per Per Cent OTI Adjusted R perm0 Ccnt Knock Per Cent Per Cent ml. Kill down Kill Kill o-Chlorophenyl0. 05 0 70 40 0 Allyl 0.1 22 91 51 21 Tetrahydrofurfuryl 0. 1 17 90 4619 I claim:

1. An insecticidal composition comprising pys'sasssesasaess rethrin anda compound represented by the formulae REFERENCES CITED The followingreferences are of record in the file of this patent:

UNITED STATES PATENTS Name Date Gertler et al Aug. 10, 1943 OTHERREFERENCES Number Beilstein, 1934, 4th ed., vol. 19, page 282. (Copy inScientific Lib.)

Harvill et al., Contributions from Boyce Thompson Institute, vol. 13,No. 2, 1943, pgs. 87 to 91.

Roark, Chemical and Engineering News; Sept. 10, 1944, pg. 1467. (Copy inLib.)

